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authorDaniel De Graaf <dgdegra@tycho.nsa.gov>2011-02-23 16:11:35 +0300
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-02-23 18:10:34 +0300
commit77c35acb7c81cd94c6b30a3bef488dd2d8145131 (patch)
treededeb89f5905567acdd66ffde0928af4c9bada26 /drivers/xen/gntdev.c
parent1f169f66ddcc3b4614f840bef367de1ca20e16fe (diff)
downloadlinux-77c35acb7c81cd94c6b30a3bef488dd2d8145131.tar.xz
xen-gntdev: Fix incorrect use of zero handle
The handle with numeric value 0 is a valid map handle, so it cannot be used to indicate that a page has not been mapped. Use -1 instead. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'drivers/xen/gntdev.c')
-rw-r--r--drivers/xen/gntdev.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 2a4733c621c0..cdc28dc8b5d9 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -126,6 +126,8 @@ static struct grant_map *gntdev_alloc_map(struct gntdev_priv *priv, int count)
add->pages[i] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
if (add->pages[i] == NULL)
goto err;
+ add->map_ops[i].handle = -1;
+ add->unmap_ops[i].handle = -1;
}
add->index = 0;
@@ -248,7 +250,7 @@ static int find_grant_ptes(pte_t *pte, pgtable_t token,
map->grants[pgnr].ref,
map->grants[pgnr].domid);
gnttab_set_unmap_op(&map->unmap_ops[pgnr], pte_maddr, flags,
- 0 /* handle */);
+ -1 /* handle */);
return 0;
}
@@ -259,7 +261,7 @@ static int map_grant_pages(struct grant_map *map)
if (!use_ptemod) {
/* Note: it could already be mapped */
- if (map->map_ops[0].handle)
+ if (map->map_ops[0].handle != -1)
return 0;
for (i = 0; i < map->count; i++) {
addr = (phys_addr_t)
@@ -268,7 +270,7 @@ static int map_grant_pages(struct grant_map *map)
map->grants[i].ref,
map->grants[i].domid);
gnttab_set_unmap_op(&map->unmap_ops[i], addr,
- map->flags, 0 /* handle */);
+ map->flags, -1 /* handle */);
}
}
@@ -280,7 +282,11 @@ static int map_grant_pages(struct grant_map *map)
for (i = 0; i < map->count; i++) {
if (map->map_ops[i].status)
err = -EINVAL;
- map->unmap_ops[i].handle = map->map_ops[i].handle;
+ else {
+ BUG_ON(map->map_ops[i].handle == -1);
+ map->unmap_ops[i].handle = map->map_ops[i].handle;
+ pr_debug("map handle=%d\n", map->map_ops[i].handle);
+ }
}
return err;
}
@@ -313,7 +319,10 @@ static int __unmap_grant_pages(struct grant_map *map, int offset, int pages)
for (i = 0; i < pages; i++) {
if (map->unmap_ops[offset+i].status)
err = -EINVAL;
- map->unmap_ops[offset+i].handle = 0;
+ pr_debug("unmap handle=%d st=%d\n",
+ map->unmap_ops[offset+i].handle,
+ map->unmap_ops[offset+i].status);
+ map->unmap_ops[offset+i].handle = -1;
}
return err;
}
@@ -328,13 +337,13 @@ static int unmap_grant_pages(struct grant_map *map, int offset, int pages)
* already unmapped some of the grants. Only unmap valid ranges.
*/
while (pages && !err) {
- while (pages && !map->unmap_ops[offset].handle) {
+ while (pages && map->unmap_ops[offset].handle == -1) {
offset++;
pages--;
}
range = 0;
while (range < pages) {
- if (!map->unmap_ops[offset+range].handle) {
+ if (map->unmap_ops[offset+range].handle == -1) {
range--;
break;
}